Pressurized flush toilets are well known and are of a variety of types. In one type, a valve is installed between a pressurized inlet water line and the inlet to the toilet bowl. Actuation of the valve effects a timed flush of the toilet bowl with water at the inlet line pressure. In another type, a volume of flush water is stored in a pressurized vessel, which may reside in the usual vitreous or plastic toilet tank of the toilet as in U.S. Pat. No. 5,046,201. In this type, the pressurized contents of the vessel are expelled to the toilet bowl to effect a flush when the outlet of the pressurized vessel is opened.
Particularly in pressurized flush toilets having a pressurized reservoir vessel, the reservoir vessel may have a number of components such as a backflow preventer, a pressure regulator and/or an aspirator which connect the vessel to a pressurized water line. These inlet devices require venting because occasionally they may emit water outside of the pressurized supply. For example, if the pressure limit of the pressure regulator is exceeded, the pressure regulator relief diverts the excess pressure from the reservoir vessel to exhaust through the vent line to atmospheric pressure Exhausting water may also occur by the normal operation of the backflow preventer and aspirator.
In toilets having a pressurized reservoir vessel within an integral tank of the toilet, as in U.S. Pat. No. 5,046,201, the vent lines of the inlet devices can be communicated with the toilet bowl directly.
However, it is desirable to be able to use a pressurized flush reservoir vessel in two piece toilets, in which the toilet tank is one piece and the toilet bowl is another, separate piece. It is also desirable to be able to easily retrofit a pressurized flush vessel to a toilet, one piece or two piece, in which no special provision is made in the toilet casting process for venting the inlet devices to the toilet bowl. Such toilets present a problem for venting the inlet devices, since there is no direct access from inside the toilet tank to the toilet bowl for venting the inlet devices. In such toilets, drainage has been provided by a check valve in the connection between the pressurized flush vessel and the toilet bowl which opened directly into the toilet tank, but such drainage has resulted in pools of standing water in the toilet tank, which is undesirable.